Some of the things doctors and patients believe to be true about whooping cough are not true at all.
Whooping
You do not have to whoop to have whooping cough. Only about half of people with typical whooping cough actually whoop, and then it is only some of the time.
It makes you feel ill
Most people with whooping cough do not feel ill. They may be exhausted from coughing and lack of sleep, but it is very different from something like influenza which causes fever and malaise. Feeling ill with whooping cough suggests some kind of complication such as secondary infection or pneumonia.
It starts like a catarrhal cold
In my studies only about one person in three describes it starting in this way. But just about every source you can find about symptoms describes it as starting like a cold. They just copy each other. In my experience gleaned by talking to 744 patients with it, only a minority seem to start that way. More usually it starts with a sore throat that becomes a dry cough that developes into a choking cough after about 10 days.
It lasts 100 days
It is more likely to last 50 days which is the average in my experience. It is said that the term ‘The 100-day cough’ is what whooping cough is called in China.
The increased numbers are just the result of better diagnostic tests
Over the last 20 years the number of cases has been increasing, especially in the USA. This has been blamed on the acellular vaccine introduced 25 years ago. There is now good evidence that it does not prevent transmission from person to person like it is supposed to. Although better tests have contributed to recently increased numbers diagnosed, there really is a resurgence of this disease.
Pertussis infection always causes whooping cough
Some people in contact with pertussis bacteria get whooping cough, especially if contact has been close, as in a family. Some get a cough that is not especially different from a viral cough. Others probably get a trivial infection that may go unnoticed. All three categories will have their immunity boosted in all probability. That is probably why whooping cough is not a big problem in adults.
The potential to transmit pertussis to others very likely depends on the severity of the cough. The bacteria are present in the aerosol from a cough and in saliva.
If you have had the vaccine you can’t get it
The vaccine is very effective at preventing infants dying from it. They are most at risk. This is the purpose of the vaccine. Older children are given boosters in case they pass it to infant siblings. The vaccine is not very effective at preventing older children and adults getting it, but severity is marginally less. It may reduce infectivity to others however. In some countries boosters are advised every 10 years. There is little evidence that it gives worthwhile protection to adults.
It is only spread by coughing
It seems fairly clear that people can be infected with pertussis and pass it on even when they have no symptoms or mild symptoms, especially if they have been immunised with acellular pertussis vaccine. It is more likely to be passed in this way between very close contacts as in the home. Coughing is probably a more important way of passing it on in less intimate circumstances.